Before diving into an extended hands-on session with Naughty Dog's The Last of Us, creative director Neil Druckmann describes what he hopes I'll take away from the demo: "We want to demonstrate through gameplay, through action what people have had to deal with." By "people," he's referring to the survivors of a population-wiping plague that took hold 20 years prior when a plant-based parasite began burrowing into human brains. As far as what those struggling few "have had to deal with," well, Druckmann's talking about the Infected.

We got a brief glimpse of this threat in the game's first trailer, but Naughty Dog has since kept the scares to a minimum while they focus on the game's world and characters. In fact, the only real enemies we've seen protagonist Joel and fellow survivor Ellie face have been a bunch of angry, hobo-looking humans. While these Hunters—as Joel dubbed them—seemed a formidable foe, they now look like cookie-baking grandmas next to the Infected.

My demo opens roughly two hours into the game. Joel and his smuggling partner Tess have accepted an assignment to sneak Ellie out of Boston's quarantined zone and deliver her to the city's capitol building. Everything outside the protected area—which has become a strict police state not above executing its rule-breaking citizens—is either destroyed or has been overtaken by an aggressive Mother Nature. Caught in a vicious downpour, the trio seek shelter while navigating bombed-out buildings, overturned subway cars, and collapsed highways.

They soon find refuge in an office complex, but a fresh corpse on the floor suggests they're not alone. It's at this point I'm introduced to the Stage 1 Infected, dubbed Runners. Druckmann elaborates: "Stage 1 is where the infection starts taking over your mind and kind of drives you mad. You're not in control of your body anymore and it's driving you to attack other people. Runners can see, they're still human, but they're doing something beyond their control." Before I engage the first of these fleet-footed freaks, Druckmann warns they also move in packs and are as agile as they are nimble. Great.

Armed with a pistol and shooting mechanics that'll feel familiar to anyone who's dropped a bandit from behind Nathan Drake's marksman skills, I'm able to down some of the creeps with slugs. They move fast and erratically, though, so getting more than the first shot off with any degree of accuracy is impossible. The rest I pop off in a state of frenzied panic. Ammo's also super scarce, so running and gunning isn't an option, ever. I find melee weapons, such as splintered 2x4s and bricks, effective, as are Joel's bare knuckles. All encounters are frantic affairs, however, that call upon a combination of shooting, running, hiding, looting, and up-close attacking. Tess helps sometimes, occasionally putting a bullet in a Runner's rotting brain just as it's about to free Joel of his jugular. Despite this hunger for flesh, Druckmann ensures these baddies are not zombies. Brain-eating is simply a by-product of their need to spread the pandemic and survive. "If they sense another person is not infected, it's their instinct to attack and try to spread the fungus."

With trigger finger instinctively twitching and nerves properly frayed, I'm afforded a bit of a reprieve to dig into the game's crafting system. Not nearly as complex as the term usually implies, crafting in The Last of Us is a streamlined, intuitive affair. As players progress through the story, they'll scavenge items—binding, scissors, alcohol, sugar, rags etc.—which can be used to cobble together weapons and supplies. A quick button-press calls up a menu displaying all inventoried ingredients as well as items ready to be built. It's important to note though, you're vulnerable while making items, so finding a safe spot before MacGyver-ing is essential. Another pro-tip: Never pass up crafting items or ammo; unlike most games, The Last of Us won't generously surprise you with an entire box of shotgun shells or a surplus of med-kits.

I quickly learn shivs, made by combining scissors and binding tape, are a great stealth weapon. In fact, the crude blades even take out Clickers, the next Infected type I encounter. Named for the terrifying sound they make with their tongues, Clickers represent the infection's third stage. At this stage the brain-burrowing parasite has grown to the point that it's poking through the host's eyeballs, rendering it blind. Druckmann grimly refers to this as "a fate worse than death." The grotesque mutation, which uses a form of echolocation to navigate the environment and track potential targets, makes the Runners look like playful puppy dogs.

Sneaking up behind them and burying a blade into their neck is the way to go, but shivs are in short supply. Shotgun blasts are effective, but attract nearby Clickers. As I progress, I find I'm relying on both stealth and aggressive strategies, utilizing various combinations of ranged and up-close attacks. Because some areas are populated by both enemy types, no single method is full proof. The Runners have their sight and are fast, but are easier to take down, while the Clickers can't see, but are attracted to sound. The odds are modestly evened by Joel's "listen" ability; the mechanic places the protagonist in a prone position, filters out all surrounding sound, and shows nearby enemies-even through walls. Objects, such as bricks and bottles, can also be tossed to distract and mislead enemies.

While my demo clearly funnels me through a specific path with conveniently placed objects, its clever design also supports sandbox-y play. I'm able to skulk around interiors to get the jump on targets and, more often, run away and regroup when encounters get too intense. While doing the latter, The Last of Us' combat depth begins to reveal itself. As a typically aggressive player, I'm quick to combine all bindings with alcohol to craft Molotov cocktails, but soon regret not saving one as a life-reviving bandage. Upon barbequing several baddies with a single Molotov, I'm confident I've crafted wisely, but Druckmann reminds maintaining a delicate balance between offense and defense is a continuous struggle.

With my demo coming to a close, I'm able to steal a quick breath as I lead Joel, Tess and Ellie to safety. Still, thanks to some of the most immersive sound work I've experienced this generation, The Last of Us never lets me truly relax; from the Runner's pattering feet to the Clickers tell-tale tongue twitch, the air always seems to be carrying some unsettling sound. Even non-threatening audio cues, like deafening shotgun blasts and the finger-nails-on-chalk-board screech accompanying the movement of environmental objects, has little trouble shooting a chill down my spine.

Previous looks at The Last of Us left me wanting to learn more about its intriguing story, setting, and character relationships. Now, after spending thirty minutes in its nightmare-conjuring world, I can add my next encounter with the Infected to that wish-list. Before leaving Druckmann, I ask if there's anything beyond the Clickers, a level of infection even more terrifying than Stage 3. Like a man who takes a bit too much pleasure in scaring the pants off people, he shoots me a sly look and says "Yeah, there's more stuff... oh yeah."

A veteran freelance journalist covering the videogame industry for nearly a decade, Matt Cabral contributes regularly to a variety of enthusiast and print outlets. You can find his work on the web, in print, and, if you look carefully, in the foam of your latte. Find him on Facebook and follow him on Twitter @gamegoat.